Benjamin Borges peered at the detailed Lego replica of Fenway Park, pushed a button and watched his hit earn a double.

“Look, mom, you can actually play this,” said Borges, 11, who attended a preview of Legoland Discovery Center Boston. “It even has vendors.”

Highly anticipated and sold out through Monday, the new attraction at Assembly Row in Somerville is the seventh in the United States to open since 2009. Developed by Merlin Entertainment, a British company which also runs Madame Tussaud Wax Museums, it’s an entertainment hybrid with Lego-inspired amusement rides, climbing gym and 4-D movies, as well as Lego urban models and Lego play areas filled with the miniature building blocks.

“It’s like jumping into the world’s largest box of Lego bricks,” said general manager David Gilmore of Plymouth. “And each new center gets better.”

The replica of Boston and its landmarks, for example, is the largest, made from more than one million parts that took a team of international designers 60 days to install. Known as Miniland, the room of dioramas is a highlight to impress adults as well as children. With sound effects, moving parts, interactive features, and a cycle of day and night lighting, it is dynamic and surprising and particularly beautiful in the dark. It has the realism of a photograph, rather than a toy, and is likely to reinforce the pride felt by so many Bostonians in the city’s past and present.

After batting at Fenway Park, Benjamin and sister, Emily Borges, 9, spun two wheels to race tiny crew boats down the Charles River in front of Harvard University. Elsewhere, visitors set off the cannons from Old Ironsides, and the water of Boston Harbor erupted when the ammunition hit. At Logan Airport, Lego Minifigures rode the moving sidewalk, and at the Hatch Shell, three musicians give a rock concert.

“This is so very well done, and I love how it’s day and night,” said Wendy Borges, Benjamin’s mother.

The Somerville site also has the most technologically advanced group orientation, which takes visitors on a digital factory tour where they see the bricks made in a Danish factory, and they can design their own Minifigures. (Lego bricks were invented in Denmark in 1932, followed by Minifigures in 1978) After the orientation, visitors explore on their own.

To expand their Lego skills, kids can receive formal instruction at workshops scheduled for the center’s classroom, the Model Builder Academy. Colby Keating, of Plymouth, is one of 12 talented designers selected from more than 600 applicants for the Junior Construction Panel. He will work once a month on new Lego projects with master builder Ian Coffey. Colby won a spot based on his creation of a Lego football stadium.

Page 2 of 2 - “It’s just really fun to build things,” said Colby, 10, a fourth-grade student at South Elementary School in Plymouth. “I’m looking forward to learning how to build bigger things and using more pieces in better ways.”

While workshops will be limited, kids at all times can build cars and race them down parallel chutes, with times recorded to the 100th of a second, as Nick Cote and Ben Calandrella, 9, did repeatedly.

“I was worried it would seem too babyish to them, so I was surprised how much they enjoyed it,” said Nick’s mother, Deb Cote. “They were into Legos a few years ago, and this might spark their interest again.”

Legoland Discovery Center is best suited for kids ages 3-10. Other attractions include two amusement rides: in one, kids travel in chariot cars through a dark maze where they try to rescue a princess by zapping Lego figure trolls and skeletons, and in the other, they pedal circling Duplo cars to rise toward the ceiling. In the three 15-minute 4-D films, water and foam shoot into the audience. The climbing structure has separate areas for children under 3 feet and up to 4 1/2 feet. There’s a also a farm area with Duplos for small children and a play house with karaoke and pink and purple Legos to appeal to girls.

For a central vantage point, parents can sit in the colorful cafe – which has an impressive 10-foot high Lego clock tower and 6-foot high Lego ice cream sundae. The cafe fare is quite expensive, and outside food is not allowed. However, a new riverside park just outside the building is comfortable for picnicking. A children’s play ground is expected to open in the park later this year.

In fact, a visit can be combined with shopping, a movie or a restaurant visit. The center is part of Assembly Row, a new 45-acre multi-use development under construction on a former industrial site which included a Ford Motor Factory.

Jody Feinberg may be reached at jfeinberg@ledger.com or follow on Twitter @JodyF_Ledger.